1. Technical Field
This invention relates generally to the assembly of wiring harnesses, and more particularly to an apparatus and method for improving the speed and efficiency with which wire harnesses are taped.
2. Discussion of the Related Art
Wire harnesses are large bundles of wire used to interconnect the electrical components of a vehicle to their respective input controls and power source. Various groupings of wires are formed in the process of building a wire harness. Some wires are grouped together because they interconnect devices lying in the same general proximity. Other wires are grouped together because they have similar operating properties, such as being high current conductors versus low current conductors. One of ordinary skill in the art can appreciate that wires can be readily grouped according to a variety of other criteria as well. The wires forming a particular group are bundled, or harnessed, to allow greater ease of assembly into the vehicle.
In the manufacture of wire harnesses for vehicles such as automobiles and aircraft, the wire harnesses have become increasingly complex. The proliferation of electrical devices and control systems has increased the number of wires needed. Further, the need to provide functional circuit protection dictates that certain critical functional circuits be electrically isolated from noncritical functional circuits. This enhances the vehicle's ability to function properly in the event of an electrical component failure but increases the complexity of the wiring task. Conversely, the need to reduce wire harness weight has necessitated interconnecting devices to one another for the purposes of sharing an input control or power source even if the devices themselves are otherwise unrelated. As a result of these completing criteria, wire harnesses often resemble an uprooted tree, with a branching root structure dividing outward in one direction from the main trunk, and with another set of branches dividing out in another direction from the main trunk.
It can be appreciated from the foregoing that the assembly of wire harnesses is a complex task. However, it is often not feasible to fully automate the assembly process due to the number of components and connectors being attached, the variety of harnesses assembled at a single factory and the degree to which wire harnesses vary to accommodate different option packages within a given model vehicle. Therefore, wire harnesses are often clipped, bundled and taped by hand. To ease the manual process of bundling wire harnesses, fixtures known as jigs are used to assist the worker in both separating and holding the wires while they are bundled.
Past jigs have proved less than optimum for several reasons. Previous types of jigs have clamps which must be manually tightened and loosened to raise and lower the jig as the work pieces are processed. This reduces the workers' efficiency because they must stop their assembly operation to clamp and unclamp the jig. It also increases fatigue in the workers because they must reach away from their work surface to operate the jig clamp. Previous jigs also were not flexible enough to accept a wide variety of wire configurations. Fixed tine heads have to be removed and changed to allow the head tine configuration to change. This decreases worker efficiency due to jig down-time during change-over. This also increases production costs because many different fixed tine heads need to be stocked to accommodate the variety of wiring configurations assembled at the plant.
For a jig to be a truly effective aid to a worker assembling a wire harness, the jig must meet several requirements. First, the jig must be easy and quick to use. It should readily lock into place for supporting the work piece without requiring the worker to stop and secure a clamp or locking mechanism, and should be capable of being moved quickly out of place as the assembly process progresses. Also, the jig must be flexible, capable of being readily adapted to deal with many different types of wire harness assembly tasks. Finally, the jig would preferably be made from inexpensive, durable materials to reduce the acquisition and maintenance costs introduced into the assembly process through the use of the jig.